The invention relates to a drive device for moving a covering element for covering an opening in a motor vehicle, in particular a roller blind, a baggage space cover or a sunroof cover and to a door assembly and a method for mounting a drive device.
Such a drive device is used, in particular, for moving a covering element in the form of a roller blind for covering a window opening in a motor vehicle door, and for this purpose it has a drive, a guide means and a thrust element which is coupled to the drive and which is guided in the guide means and can be connected to the covering element in order to move the covering element.
EP 1 123 824 A2 discloses a side window roller blind for motor vehicles which makes use of such a drive device. The drive device according to EP 1 123 824 A2 has a guide means in the form of two guide rails which are arranged vertically on a vehicle door and along which a carriage is guided, which carriage is connected to an upper, horizontal bar, referred to as the bow, of the roller blind web of the roller blind. The carriage is coupled to a thrust element which has, on its outer circumference, a worm toothing in which a pinion of a drive engages and moves the thrust element in order to activate the roller blind. The roller blind web of the roller blind is wound onto a winding shaft in a door breastwork of the vehicle door and can be guided out of the door breastwork through a horizontal slit in the door breastwork and be pulled into the region of the window opening by means of the thrust element and the carriage in order to cover the window opening. During this operation, the roller blind web is unwound from the winding shaft and in the extended state it covers the window opening in such a way that the incidence of light through the window opening is prevented or at least attenuated, and vehicle occupants are therefore protected against solar radiation.
The drive device according to EP 1 123 824 A2 uses guide rails which extend in the region of the window opening. For reliable operation of the roller blind, two lateral guide rails are necessary, along which the roller blind web of the roller blind is pulled and moved into its position in which it covers the window opening. The lateral guide rails are absolutely necessary here in order to guide and stabilize the upper roller blind edge and the carriages. However, only a small installation space is available for the guide rails, with the result that the installation of the roller blind is notably connected with widening of the frame trim or of an intermediate web in the case of a divided window pane, which entails a reduction in the window pane surface and thus in the viewing range of a vehicle occupant and is associated with a considerable degree of expenditure on mounting in order to attach the guide rails and necessary trim elements. At the same time, the external appearance of the window frame may be adversely affected in esthetic terms by the guide rails which project into the region of the window.